Rotary power should be smoothly and regularly transmitted to components within an image forming device. This includes transmitting rotary power from a drive mechanism in an image forming device to elements that may be removable from the image forming device, such as developer cartridges. The rotary power and operation of the removable element is controlled through the image forming device itself.
It is important that the connection between the removable element and the image forming device allow for accurate control. Previous image forming devices have used various coupling designs in an attempt for accurate control. However, these designs often resulted in disengagement between the removable element and the image forming device. Disengagement interrupts the smooth and regular transmission of the rotary power, and adversely affects the quality of image formation. Further, once the removable element and image forming device start to periodically disengage, the frequency of disengagement slowly increases as the interface progressively wears. Thus the progressive wear causes more frequent print defects.
Thus, there exists a need to transmit rotary motion reliably and accurately from the drive mechanism of the image forming device to the removable element.